/*
 * -\-\-
 * Mobius
 * --
 * Copyright (c) 2017-2020 Spotify AB
 * --
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * -/-/-
 */
package com.spotify.mobius;

import static com.spotify.mobius.internal_util.Preconditions.checkNotNull;

/**
 * Indicates that a {@link Connectable} connection caused an unhandled exception.
 *
 * <p>This is a programmer error - connections must never throw unhandled exceptions, instead the
 * connection is expected to catch the exception and emit a special error value to its output
 * consumer.
 *
 * <p>An example of this would be that if loading an HTTP request throws an exception, then the
 * connection should emit a LoadingDataFailed event to communicate the failure to {@link Update}.
 */
public class ConnectionException extends RuntimeException {

  private final Object effect;

  public ConnectionException(Object value, Throwable throwable) {
    super(checkNotNull(value).toString(), throwable);

    this.effect = value;
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (!(o instanceof ConnectionException)) return false;

    ConnectionException that = (ConnectionException) o;

    return effect.equals(that.effect);
  }

  @Override
  public int hashCode() {
    return effect.hashCode();
  }
}
